> Question: “Shopping for shoes, I came across some kind of a nanobased shoe care spray. The substances contained are distributed as aerosols whose potential hazards are discussed in numerous articles. Considering this and the present state of knowledge, is it justified to have such sprays approved?”
Since consumer safety has priority, the approval of such products is subject to legal regulations. In spite of this, however, legislation cannot always check and verify all substances, and dubious products may well appear on the market. Due to the very fine aerosols and containing solvents and active components compressed-gas sprays are often labeled as hazardous to health and should be used according to instructions.
Classification and approval have been required even before such “nanosprays” have been existing. Serious accidents already happened in the 70s of the 20th century with leather sprays or textile sprays, i.e. with surface-active substances applied to leather or to textiles. The fine mists of these products are easily inhaled by the consumer to settle down in parts of the lung tissue and impair health. This is also true for sprays containing the alleged “nanoparticles”, since sprays of that kind also depend on the use of additives and solvents. The pressurized dispensers are marked ”harmful to health“ and should be used outdoors, protected from the wind! To our knowledge, there are not any sprays available that really contain nanoparticles.